I'm interested in looking for a way to make swordcraft 2 get undubbed. As some of us know that the dubbed version of eng is not that great.. SO Im wondering if its possible to replace the voice files with the original JP dub?

I've tried with several methods so far, with the gba_audioripper by atrius, but it just puts the sounds to the end of file, while with sappy I can change the sounds and bgm and even the bgm of swordcraft3, but I can't seem to find the voices... can the voices even be displayed with sappy, but is one of those blurry sound files? Or its not possible at all?
The other alternate method I can think of is like dump all the english text and then put it into the JP one... but won't that take LONG?

Redoing the translation... hard to say how long/hard that will be. I imagine you will have to backport a fair bit though (font, font/text handling and the usual fun with pointers) so yeah I would consider it a last resort especially if an undub will do what you need.

The GBA does have a somewhat common sound format usually known as sappy (some info/links http://gbatemp.net/t230202-gba-sappy-sound...ion-by-bregalad ) but it is not quite as common as some formats you might see on other consoles (certainly if I pull apart a GBA rom and it does not use it then it barely registers as odd unlike say the DS).

Tool with outside ripping and game specific stuff aside (mainly some of the stuff Atrius was doing with golden sun, the fire emblem stuff, maybe some advance wars and whatever is going on in pokemon and for the sake of a hex compare final fantasy as well) though it is something of a manual process even compared to the DS and the odd system does use a hybrid format with sappy and something custom for other things- I am willing to bet however that the voices if they are not detected as sappy are fairly simple though.

To this end you are probably going to want to look at some tracing http://www.romhacking.net/docs/361/ to find what calls the voices and where from (the GBA has a measure of hardware support and only the foolish commercial developers ignore it or try to do anything truly custom- http://nocash.emubase.de/gbatek.htm#gbasoundcontroller ). It might be two step as well (DMA audio channels at least according to gbatek look to "prefer" internal memory rather than cart based (although it might still happen).

By the looks of things I probably said nothing you did not already know or want to think about (it is probably going to be a full manual job with the only tools being the output of your debugger and whatever it guides you searches to).